| 101 | Dale Operating Company | Dallas, TX 75207 | Oil & Gas Operator | May 2026 |
| 102 | Dao Oil And Gas | Carrizo SPGS, TX 78834 | Oil & Gas Operator | May 2026 |
| 103 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | May 2026 |
| 104 | Devilbiss Contracting, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Oct 2005 |
| 105 | Dimmit County SWD, LLC | Carrizo SPGS, TX 78834 | Oil Operator | May 2026 |
| 106 | Dirnett, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | May 2026 |
| 107 | Dixon Exploration Inc | Abilene, TX 79604 | Oil & Gas Operator | Oct 2019 |
| 108 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 109 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | May 2026 |
| 110 | Double J Operating Company, Inc. | San Antonio, TX 78205 | Oil Operator | Jan 2008 |
| 111 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | May 2026 |
| 112 | Double U Oil Co. | San Antonio, TX 78217 | Oil & Gas Operator | Feb 1996 |
| 113 | Double U Oil Co., LTD. | San Antonio, TX 78217 | Oil & Gas Operator | May 2000 |
| 114 | Douglas Investments Inc | Fort Worth, TX 76137 | Oil Operator | Jan 2020 |
| 115 | Douglas Petroleum Inc. | Spring, TX 77379 | Oil & Gas Operator | Nov 2010 |
| 116 | Duplantis Energy, LLC | Pleasanton, TX 78064 | Oil Operator | May 2026 |
| 117 | Eagle Energy Resources, LLC | La Porte, TX 77571 | Oil & Gas Operator | May 2026 |
| 118 | Eagle Ford Oil Co., Inc. | Houston, TX 77057 | Oil & Gas Operator | May 2026 |
| 119 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | May 2026 |
| 120 | Edisto Resources Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 1999 |
| 121 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 122 | El Toro Resources LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | May 2026 |
| 123 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Feb 2026 |
| 124 | Ellsworth, H. P. O&G Properties | Corpus Christ, TX 78413 | Oil & Gas Operator | May 2026 |
| 125 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Feb 2026 |
| 126 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 127 | Endeavor Natural Gas, LP | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 128 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2025 |
| 129 | Energy Frontiers Partners, LP | Grapevine, TX 76051 | Oil Operator | May 2008 |
| 130 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Jan 2026 |
| 131 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2026 |
| 132 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2026 |
| 133 | Enre Corp. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2005 |
| 134 | Enre LP | Kingwood, TX 77339 | Oil & Gas Operator | Feb 2004 |
| 135 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 136 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 137 | EP Energy E&P Company, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 138 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 139 | Escondido Operating, Inc. | Carrollton, TX 75011 | Oil & Gas Operator | Jun 2013 |
| 140 | Escondido Resources GP, LLC | Midland, TX 79708 | Oil & Gas Operator | Dec 2007 |
| 141 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 142 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 143 | European-Southwest Co. | Houston, TX 77254 | Oil & Gas Operator | May 2026 |
| 144 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | May 2026 |
| 145 | Exotic Oil & Gas LLC | Indiana, PA 15701-3634 | Oil & Gas Operator | Dec 2025 |
| 146 | Expand Oper LLC | Morgantown, WV 26508 | Oil & Gas Operator | Feb 2026 |
| 147 | Exploration Company, The | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2010 |
| 148 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | May 2026 |
| 149 | F & M Oil Company Inc | Pettus, TX 78146 | Oil & Gas Operator | May 2026 |
| 150 | Famcor Oil, Inc. | Scottsdale, AZ 85260 | Oil & Gas Operator | Sep 2020 |
| 151 | Fenn, Bill Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2008 |
| 152 | Field Petroleum Corp. | San Antonio, TX 78216 | Oil & Gas Operator | May 2026 |
| 153 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | May 2026 |
| 154 | First Rock, Inc. | Corpus Christ, TX 78401 | Oil & Gas Operator | May 2026 |
| 155 | Flint Oak Energy, LLC | Montgomery, TX 77356 | Oil & Gas Operator | May 2026 |
| 156 | Flournoy Production Co. | Alice, TX 78333 | Oil & Gas Operator | Dec 2002 |
| 157 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 158 | Formentera Operations LLC | Austin, TX 78701 | Oil & Gas Operator | May 2026 |
| 159 | Forney Oil Corporation | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 160 | Forster, Fred Jr. | Midland, TX 79705 | Oil & Gas Operator | Aug 2008 |
| 161 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2026 |
| 162 | Freedom Energy Inc | Horseshoe Bay, TX 78657 | Oil & Gas Operator | May 2026 |
| 163 | Frio Exploration Company | Pearland, TX 77588 | Oil & Gas Operator | Dec 2000 |
| 164 | Fulcrum Energy Operating, LLC | Denver, CO 80206 | Oil & Gas Operator | May 2026 |
| 165 | FW Eagle Ford I, LLC | Houston, TX 77084 | Oil & Gas Operator | May 2026 |
| 166 | Gassco Petroleum Corporation | Seguin, TX 78155 | Oil & Gas Operator | May 2026 |
| 167 | General Atlantic Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 168 | Genesis Well Service | Colleyville, TX 76034 | Oil Operator | May 2026 |
| 169 | Ginco Operating Co. | San Antonio, TX 78217 | Oil & Gas Operator | May 2026 |
| 170 | Glenco Oil & Gas Company | Seguin, TX 78155 | Oil & Gas Operator | Dec 1994 |
| 171 | GLG Energy LP | Austin, TX 78701 | Oil & Gas Operator | Jun 1994 |
| 172 | Global Natural Resources Corp. | Houston, TX 77002 | Oil & Gas Operator | May 1998 |
| 173 | Golden Child, Inc. | San Antonio, TX 78213 | Oil & Gas Operator | May 2026 |
| 174 | Grit Oil & Gas Management, LLC | Houston, TX 77055 | Oil & Gas Operator | Feb 2026 |
| 175 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 176 | Gulf Production Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2015 |
| 177 | Gulftex Energy, LLC | San Antonio, TX 78257 | Oil & Gas Operator | May 2026 |
| 178 | H & M Resources LLC | Dallas, TX 75225 | Oil & Gas Operator | May 2026 |
| 179 | H R E Rental Company | Premont, TX 78375 | Oil & Gas Operator | Sep 2015 |
| 180 | Hamilton, Clay | Carrizo SPGS, TX 78834 | Oil & Gas Operator | May 2026 |
| 181 | Hamilton, J. R. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | May 2026 |
| 182 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 183 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | May 2026 |
| 184 | Heartland Resources, Inc. | Temple, TX 76501 | Oil & Gas Operator | Mar 2008 |
| 185 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 186 | HMX Investments, Inc. | Katy, TX 77494 | Oil & Gas Operator | Jan 2026 |
| 187 | Holifield Oil Company | Giddings, TX 78942 | Oil & Gas Operator | Mar 2009 |
| 188 | Holley Oil Company, LLC | Chappell Hill, TX 77426 | Oil & Gas Operator | May 2026 |
| 189 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 190 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 191 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 192 | Huber Energy L.P. | Houston, TX 77079 | Oil & Gas Operator | Feb 2007 |
| 193 | Huber Energy Panhandle LP | Houston, TX 77079 | Oil & Gas Operator | Oct 2005 |
| 194 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | May 2026 |
| 195 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 196 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | May 2026 |
| 197 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 198 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | May 2026 |
| 199 | Icarus Operating Corporation | Spring, TX 77393 | Oil & Gas Operator | May 2026 |
| 200 | Ineos USA Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | May 2026 |